Shahlaei started strongman training in 2005 and entered his first novice competition that year, where he finished 8th. Within two years, he entered his first Britain's Strongest Man ("BSM"), having won the Midlands qualifier. In that competition, he made a huge impact, making it to the final, only to tear his biceps in the tyre flip, which forced him to withdraw. He won the Midlands qualifier again in 2008, and once again made the final, this time finishing 4th behind Jimmy Marku, Terry Hollands, and Mark Felix. This placing landed him an invite to the World's Strongest Man in 2008. Despite his impressive win in the squat, he did not make the final.

In 2009, just four years after beginning strongman, he became the UKSC Midlands Strongest Man and also won the UKSC England's Strongest Man, citing this, alongside his WSM 2008 squat win, as the greatest moment of his career (the WSM qualifier titled "England's Strongest Man", which replaced the Britain's Strongest Man contest in 2009, was won by Terry Hollands and Shahlaei did not compete in that). His favourite strongman event is the farmer's walk because it is a good test of natural strength, whereas his least favourite strongman event is the Atlas stones. Shahlaei has said that he admires Bill Kazmaier and Vasyl Virastyuk for their intensity and belief in themselves, qualities he seeks to emulate, and that he believes the greatest strength athlete of all time is Zydrunas Savickas.